Scaling stateful clusters while maintaining access

A stateful cluster may implement scaling of the stateful cluster while maintaining access to the state of the stateful cluster. A scaling event for a stateful cluster may be detected, and in response the stateful cluster may be adjusted to include a different number of nodes. The state of the cluster may then be logically distributed among the different number of nodes according to a monotone distribution scheme. The adjusted node may then service access requests according to the monotone distribution scheme. Prior to making the adjusted storage cluster available for servicing access requests, the nodes from the original cluster may still service access requests for state.